Sultan: Not at 1.11Vne.
Look The Advisory Circular defines the testing requirements and is online. Have a read and you'll see what they had to do, and, important to your implication, not do.
Re the R/W note above. Doing the OEI Vne testing by itself would explain some Nr droop, but typically not result in the comment " significantly "*. The comments re the blades going out of track and the possibility of both nose and tail strikes opens up all sorts of possibilities, but one needs the telemetry data to make sense of what was going on.
*The FAA does not require simultaneous twin engine cuts on a twin engine Cat A machine. The military does, dependent on the rules set up for the particular aircraft. One day the Project Pilot on the CH-53D asked me if I was doing anything ( I wasn't ) and he needed me to help him do the twin cuts at max speed, max weight, with appropriate pilot delay time. Now that defined significant rotor speed droop ( high 70 % as I recall ). I still have a copy of the data traces. The aircraft rolled left very quickly and in fact my right leg got whacked pretty good when Frank put in full right cyclic. But the blades remained in track etc. Now, we had done a buildup at incremental speeds up to the max speed point and things had gone quietly, so the reaction at the final data point was without prior evidence that we were on the edge ( of rather severe stall ). This is not a suggestion at all re the Bell 525 situation, simply an observation that significant Nr droop ( depending on how the writer defines " significant " ) needs an explanation.
We can be certain that all of these aspects have already been examined in detail by the Bell investigative folks.
Last edited by JohnDixson; 26th Jul 2016 at 14:25.
Reason: Additional thought x 2